Re: Intermittent NXDOMAIN for a name we are forwarding

2016-02-20 Thread Matus UHLAR - fantomas
On 19.02.16 17:08, blrmaani wrote: We have a DNS setup where we forward a name in one domain to 5 external nameservers. We see NXDOMAIN error intermittently (once in couple of weeks). How do I debug this issue? tcpdump? I took a cache dump on our DNS and 2 out of 5 nameserver IPs appear in

Re: Tuning for lots of SERVFAIL responses

2016-02-20 Thread Grant Taylor
On 02/18/2016 07:05 PM, Tony Finch wrote: Yep, mostly waiting for replies that will never come, which doesn't require much CPU. Is there anything that the networking team can do to help alleviate some of the pain? I.e. make sure that equipment returns no route to host error messages? Will t

Re: A Zone Transfer Question

2016-02-20 Thread Grant Taylor
On 02/19/2016 08:04 PM, John Miller wrote: In the case of dynamic updates, one NS record might actually be better: there's no worrying about update forwarding between slave and master. It's been my painful experience that (particularly Windows) clients send dynamic DNS updates to the MNAME lis

Re: Intermittent NXDOMAIN for a name we are forwarding

2016-02-20 Thread Mark Andrews
In message <20160220172148.ga26...@fantomas.sk>, Matus UHLAR - fantomas writes: > On 19.02.16 17:08, blrmaani wrote: > >We have a DNS setup where we forward a name in one domain to 5 external > > nameservers. We see NXDOMAIN error intermittently (once in couple of > > weeks). How do I debug this